Deglaciation of the north American ice sheet complex in calendar years based on a comprehensive database of chronological data: NADI-1

Neutral markers reveal complex population structure across the range of a widespread songbird

“…When examining historic patterns of gene flow, our LGM models found the majority of suitable mountain bluebird habitat throughout the Pacific Northwest and interior southwest. Although icefree corridors likely existed east of the Rockies in Alberta (Beatty & Provan, 2010;Bednarski & Smith, 2007;Dalton et al, 2023;Dyke et al, 2002;Golden & Bain, 2000;Shafer et al, 2010), a putative southwestern Albertan refugia did not appear to have suitable habitat for mountain bluebirds. Likewise, our models also failed to support a refugia located in Beringia.…”

“…During the Pleistocene (2.58 myBP-11.7 kyBP), the planet experienced repeated cycles of cooler periods with glacial expansion, and warmer interglacial periods. North America was dominated by three expansive ice sheets ~25 kyBP (Dalton et al, 2023): the Laurentide ice sheet east of the Rocky Mountains to the Atlantic Coast of Canada, the Innuitian ice sheet in the far north and the Cordilleran ice sheet west of the Rocky Mountains to the Pacific Coast (Blaise et al, 1990;Dalton et al, 2022;Dyke, 2004;Dyke et al, 2002). Many species were forced to retreat into isolated pockets of suitable habitat known as refugia (Haffer, 1969), with genetic data supporting the presence of multiple northern refugia including Beringia and the Pacific Northwest for plants (Abbott et al, 2000;Abbott & Comes, 2004;Anderson et al, 2006;Brunsfeld et al, 2001;Shafer et al, 2010;Soltis et al, 1997;Thompson & Whitton, 2006;Tremblay & Schoen, 1999), birds (Barrowclough et al, 2004;Lait & Burg, 2013;van Els et al, 2012), and mammals (Brunsfeld et al, 2001;Leonard et al, 2000;Steppan et al, 1999).…”